| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 23.36 | 30 |
| 2015 | 23.07 | 29 |
| 2014 | 22.59 | 28 |
| 2013 | 22.06 | 25 |
| 2012 | 21.53 | 19 |
| 2011 | 21.09 | 12 |
| 2010 | 20.8 | 11 |
| 2009 | 20.6 | 10 |
| 2008 | 20.63 | 10 |
| 2007 | 20.86 | 11 |
| 2006 | 21.16 | 11 |
| 2005 | 21.44 | 10 |
| 2004 | 22.33 | 11 |
| 2003 | 23.31 | 13 |
| 2002 | 24.34 | 15 |
| 2001 | 25.42 | 17 |
| 2000 | 26.59 | 19 |
| 1999 | 27.7 | 23 |
| 1998 | 28.74 | 24 |
| 1997 | 29.72 | 27 |
| 1996 | 30.68 | 29 |
| 1995 | 31.64 | 30 |
| 1994 | 32.07 | 30 |
| 1993 | 32.36 | 28 |
| 1992 | 32.47 | 28 |
| 1991 | 32.41 | 28 |
| 1990 | 32.18 | 27 |
| 1989 | 32.23 | 26 |
| 1988 | 32.22 | 24 |
| 1987 | 32.18 | 22 |
| 1986 | 32.02 | 20 |